Automatic leveling system for elevators



g- 1938- J. H. BARTHOLOMEW I 2,125,876

AUTOMATIC LEVELING SYSTEM FOR ELEVATORS Filed Oct. 10, 1956 3 Sheets-Sheet 1 1 N VENTOR.

ATTORNEY.

Aug. 9, 1938.

J. H. BARTHOLOMEW AUTOMATIC LEVELING SYSTEM FOR ELEVATORS s Sheets-Sheet 2 Filed Oct. 10, 1936 INVENTOR. J/Wfli fiKB/I/fT/VOLO/VEW 9; 1938. J. H. B ARTHQLQ-MEW 2,125,816

AUTOMATIC LEVELING SYSTEM FOR ELEVATORS INVENTOR.

ATTO EY.

Patented Aug. 9, 1938 UNH'EED STz -t'iEx @Fililil AUTOMATIC LEVELING SYSTEM FOR ELE- VATORS 19 Claims.

The present invention relates to an automatic leveling system for elevator cars and more particularly to an electro-mechanical type of automatic leveling system.

Although automatic leveling systems for elevators are known, the present practice is to employ controls which are fully electrical and which include complicated and expensive electrical equipment and circuits and which are comparatively expensive to install and maintain.

The primary object of the present invention is the provision of an electro-mechanical automatic leveling system for elevators which is simple in construction and essentially mechanical in operation.

Another object of the invention is an electromechanical leveling system for an elevator car adapted to be leveled with respect to a plurality of floors or landings, which is mechanically and easily adjusted and which is economically maintained.

A further object is the provision of a leveling relay corresponding to each floor of the elevator hatchway, which is operative only when the ele vator car is adjacent the respective floorand which is mechanically controlled by the position of the elevator car with respect to said floor.

Still another object of the invention is the pro vision of a leveling relay including a pair of control contacts, an armature carrying one of said contacts, a magnetic coiljfor attract'ing" said armature, and a contact arm carrying the other of said contacts and moved to open the same when the elevator car is level with the floor even though said magnetic coil is still energized.

Other and further objects of the invention will be suggested to those skilled in the art by the accompanying disclosure. I

To attain the said above and other objects,

the invention consists'in certain improvements and combinations of parts an as fully set forth in the following specification and defined in the appended claims.

Reference is hereby made to the accompany ing drawings wherein like reference characters designate similar elements and wherein:

Fig. 1 is a complete diagrammaticillustration of the invention including the essential mechan- 55) ical members as well necessary electrical circuits.

Fig. 2 is a side elevation of the leveling relay and limit .arms for one floor and showing the relay in inoperative condition.

55 Fig. 3 is a side elevation similarv to Fig. 2 but phase source of electric power with the leveling relay shown as when the elevator car is level with the corresponding floor.

Fig. l is also a side elevation similar to Fig. 2 but with the leveling relay shown as when the elevator car is approaching the corresponding 5 floor.

Fig. 5 is a front elevation of the leveling relay and limit arms for a floor and with the same in positions also shown in Fig. 4 as when the elevator car is approaching the corresponding floor. iii

An elevator system according to the present invention is diagrammatically illustrated in Fig, 1 and may be installed in a structure iii which is provided with a hatchway ii. A plurality 0': floors or landings i2a, I21) and lZc are spaced along said hatchway II and a pair of hatchway doors l3 are mounted at each of said floors or landings.

The elevator car M is guided within said hatchway II in any suitable and conventional 20 manner. A cable drum 1 5 may be mounted above the hatchway l I and may be encircled by a main cable l6 which has one end attached to the car I4 and the other 'end attached to a counterweight l! moving in said hatchway l i and counterbalancing said car l4. Said elevator car M may be raised and lowered by rotation of said cable drum l5 which is operated through any known type of connection, such as a gear train, by a suitable prime mover, such as an electric 39 motor l8. Said motor i8 is connected by a. shaft l9, indicated by the broken line in Fig. 1, to a worm 20 which meshes with a worm wheel 2| in turn connected to a cable drum l5 by a shaft 22, also indicated by broken lines in Fig. 1. though the invention is to be described with respect to a traction type elevator drive from an electric motor to the elevator car, it is understood that the invention is equally applicable to all types of drives and prime movers now known 40 to the art.

The'electric motor i8 is preferably of the three phase, two speed type and has a high speed winding 23 and a low speed winding 24. A three is available through the supply mains Ll, L2 and L3. The motor circuits are conventional, are connected across said supply mains Ll, L2 and L3, and. are illustrated by heavy lines in Fig. 1.

The high speed motor circuits comprise a conductor 25 extending from supply main L! to one leg of high speed winding 23 and including a pair of contacts 26 and a pair of contacts 2?, a conductor 28 extending from supply main L2 to another leg of high speed winding 23 and including a pair of contacts 29, and a conductor 30 extending from supply main L3 to the other leg of high. speed winding 23 and including a pair of contacts 3|. Said high speed winding 23 of the motor I8 is reversed by reversing the connections of supply mains LI and L3 thereto. For this purpose, a conductor 32 extends from a point of conductor 25 to a point on conductor and includes a pair of contacts 33, and a conductor 34, including a pair of contacts extends from a point on conductor 30 to one of contacts 21 through which it is connected to conductor 25.

The low speed motor circuits comprise a conductor 36 which is connected through conductor 25 to supply main LI, which extends to one leg of low speed winding 24, and which includes a pair of contacts 31, comprise a conductor 38 which is connected through conductor 28 to supply main L2, which extends to another leg of low speed winding 24, and which includes a pair of contacts 39, and comprise a conductor 40 which is connected through conductor 30 to supply main L3, which extends to the other leg of low speed winding 24, and which includes a pair of contacts 4|. Reversal of said low speed winding 24 may be accomplished through a conductor 42 which includes a pair of contacts 43 and which is between conductors 36 and 40 to connect the last mentioned leg of said low speed winding 24 to supply main LI, through a conductor 44 which includes a pair of contacts 45 and which is between said conductors 36 and 40 to connect the first mentioned leg of low speed winding 24 to supply main L3, and through a conductor 46 which includes a pair of contacts 41 and which bridges a portion of conductor 38 to connect the middle leg of low speed winding 24 to supply main L2.

The motor control circuits may be connected between supply mains LI and L2 and include a car switch 48 including a pair of up terminals 49 and 50 and including a pair of down terminals 5| and 52. Wires 53 and 54, respectively, connect terminals 49 and 5| to supply main LI, while a wire 55 connects up terminal 50 to supply main L2 and a wire 56 connects down terminal 52 to supply main L2. A wire 51 is connected to supply main L2, has a branch 58 which includes a pair of contacts 59 and which is connected to wire 55, and has a branch 60 which includes a pair of contacts 6| and which is connected to wire 56.

An up contactor 62 includes a coil 63 which is in series with wire 55 and includes a rod 64 which is operated by said coil 63 and which carries a contact arm 65 for bridging contacts 59, a contact arm 66 for bridging contacts 26, and a contact arm 61 for bridging contacts 3|. A down contactor 68 includes a coil 69 which is in series with wire 56 and includes a rod 10 which is operated by said coil 69 and which carries a contact arm 1| for bridging contacts 6|, a contact arm 12 for bridging contacts 35, and a contact arm 13 for bridging contacts 33.

The motor control circuits for the low speed operation of the elevator car I4 include a bus wire 14 which is the only connection between supply main L2 and said low speed motor control circuits and which includes a pair of contacts 15. A high speed control contactor 16 includes a coil 11 which is in series with wire 51, includes an armature 18 operated by said coil 11, includes a rod 19 which is attached to said armature 18 and which carries a contact arm for closing contacts 29 and a contact arm 8| for closing contacts 21, and includes a rod 82 also attached to armature 18 and carrying a contact arm 83 for closing contacts 15. A spring 84 is connected to said contact arm 83 normally to hold the same in closed position and said contact arms 89 and BI in open positions.

An up leveling contactor 85 comprises a coil 86, an armature 81, and a rod 88 carrying a contact arm 89 for closing contacts 39, a contact arm 90 for closing contacts 4|, and a contact arm 9| for closing contacts 31. A down leveling contactor 92 comprises a coil 93, an armature 94, and a rod 95 carrying a contact arm 96 for closing contacts 41, a contact arm 91 for closing contacts 45, and a contact arm 98 for closing contacts 43. Said leveling contactors 85 and 92 are of a well known type with armatures 81 and 94 both normally biased to open positons but adapted to be moved to closed positions upon energization of the respective coils 86 and 93.

The energization of said up and down leveling contactors 85 and 92 is supervised by a plurality of control circuits and by a plurality of leveling relays 99, each of which 99a, 99b and 990 corresponds to each of floors I2a, I21) and I20 in the ber I00 to which is attached a bracket IOI and a magnetic coil I02. Said bracket IilI has a pair of journals I03. An armature I04 includes an arm I05 which is pivoted between said journals I03 by a pin I06 and includes a contact support I01 which is fastened to arm I05 and which carries two motor control contacts I08 and I09.

The motor control contact I 08, see Figs. 2, 3 and 4, is mounted on a stem I I0 which has a threaded end passing freely through contact support I01 and carrying an adjustable nut I I I. A coil spring I I2 encircles stem III) and normally urges contact I08 to an extended position with nut III against said support I01, which extended position of motor control contact I08 may be varied by adjustment of nut III. Contact I09 is also resiliently and adjustably supported in an identical manner by a stem I I3 and nut I I4, see Fig. 5.

Armature I04 includes abutments II5 which comprise a T-shaped arm I I6 fastened to arm I05 and carrying a pair of adjustable thumb screws H1 and H8. Said armature I04 and abutments II5 are normally in the position shown in Fig. 2.

A pair of bearings H9 and I20 are mounted on said base member I00, a contact arm I2I is journaled on bearing II9 by a pin I22, and a contact arm I23 is journaled on bearing I20 by a pin I24. A motor control contact I25 is mounted upon the upper end of contact arm I2I by a stem I 26 which is threaded into said contact arm I2I and locked in an adjusted position by nut I21. A motor control contact I28 is mounted upon the upper end of contact arm I23 by a stem I29 which is threaded into said contact arm I23 and locked in its adjusted position by a nut I30, see Fig. 4.

The lower end of contact arm I 2| has a portion I3I which is provided with a bifurcated end for supporting the axle I32 of a roller I33 while a roller I34 is similarly supported upon the lower end of portion I35 of contact arm I 23, see Fig. 4. The contact arms I2I and I23 are so proportioned and balanced upon their respective bearings H9 and I20 that both of said contact arms I2I and I23 have a normal tendency to rotate in a clock-wise direction. Stops are respectively provided to limit this normal movement of the contact arms iii and I23 and may each comprise a thumb screw use extending through base member m8 and adjustably fastened thereto by nuts [3]. Similarly stops are also respectively provided to limit the rotation of the contact arms till and its in a counter-clockwise direction and may each comprise a thumb screw E38 extending through base member E63 and adjustably fastencd thereto by nuts ltd.

Resilient members are mounted between said armature ass and the respective contact arms 52! and H33 normally to separate the contacts thereon. For instance, a leaf spring MS may be fastened on contact support liil opposite contact arm l2! so as not to engage the same when the magnetic coil M32 is not energized, see Fig. 2, but adapted to bear on said contact arm li'il and tending to separate motor control contacts Hi8 and H25 as shown in Fig. 3 when the magnetic coil I532 is energized. A second leaf spring t il may also be fastened to contact support Mil oppo- Site contact arm E23 and tends to separate motor control contacts Hi9 and W8 upon energization of said coil H32, see Fig. 5.

As before mentioned. there are leveling relays 99a, 99b, and 990 corresponding to each of the floors l lzb, and Me. Only the essential elements of said leveling relays 9530!, $917, and 99c are shown in the diagrammatic illustration of Fig. 1 and each element shown therein is designated by the general reference numeral and an alphabetical character corresponding to the floor 112a, i217 or l2c at which the relay controls leveling.

A mechanical control means operated by the elevator car M supervises the energization of the magnetic coil iii? of the leveling relay 99 as well as the positions of contact arms l2! and M3 as said car iii approaches or stops at a floor or landing.

Such. a mechanical control means includes a control drum i l-2 mounted above the hatchway H and encircled by a control cable M3 which is fastened to the car M by a bracket 5M and Which is maintained under tension by a pulley M5 and a weight see Fig. 1. A shaft Ml is journaled in bearing M3 and is attached to One end of control drum M2. A gear M9 on shaft Ml meshes with a gear 558 on a shaft lfii which is iournaled in bearings E52. The ratio between gears M9 and H9 is selected so that shaft iii-i makes less than one complete revolution, or turns through about 340, during travel of the elevator car it along the entire height of the hatchway ii. A plurality of zone arms 553 are mounted in angular relation upon said shaft iol and are each adjustable upon said shaft l5! by means of set screws lEel. Each zone arm l53c, Hi h and see Fig. 1, corresponds to each floor 52a, 52b and lilo.

Said mechanical control means also includes a shaft journaled in bearings Hi6 and attached to the other end of control drum M2. A plurality of pairs limit arms l5? and 558 are adjustably fastened to shaf 555 by representative set screws 559 and 5%, see Fig. 5. An arcuate sector 16i i mounted upon the end of limit arm i5? and an arcuate sector 562 is mounted upon the end oi. limit arm Said limit arms E57 and are angularly displaced with respect to each other so that a is provided between the ad.- jacent ends of said arcuate sectors ifil and 662, see Figs. 2, 3 and 4. Said limit arms it)? and E56 are also spaced longitudinally of said shaft I55 so that the arcuate sector It! on limit arm I57 may engage the roller !33 on contact arm I, see l, while the other contact arm l23 assumes its normal position abutting against the respective thumb screw 53%, or alternatively arcuate sector M2 on. limit arm may engage the roller lt i on contact arm 523. Furthermore, said limit arms t a l and 5&3 are also adjusted on shaft 555 so that when car is exactly level with the floor E2, the gap between said arcuate sectors will be opposite said rollers i153 and i3 5 so that both contact arms l i and E28 will rest against thumb screws 53 as shown in Fig. 3. The radial extent or" limit arms 55? and I58 rote sectors Mil and M52 may be greater 1 l than the radius of control As will be readily understood, the accuracy of the leveling operation is increased when l e it oi said limit arms is greater lius of drum because the extremilimlt arms l5? and E58 are then than car speed and the movement car l is magnified at the end-s of said limit so that said rollers H33 and l. ated herein, the limit arms l5? and we rotate in a clockwise direction when the car 5 moving upwardly and in a counter-clockwise recti when car it is moving downwardly, see arrows Figs. 2, 8 and l. Also the zone is in icated by the arrows as rotating in a counter-clockwise direction when the car is moving upwardly. However, it is to be understood that said arms may rotate in either direction as long as their relative timing meets the conditions later to be set forth.

A. plurality of pairs of limit arms lbla and 65% and i582), and idle and 85550 are provided on shaft 555 and each pair corresponds to one of the floors lilo, l2?) and We, see Fig. 1. It is obvious that when the magnetic coil m2 of each leveling relay Qt is not energized that the contact 512i and on each relay 99 are ntained the posit ons illustrated in Fig. 2 by the abutments M5 on armature Hi4 so that there is ample clearance between rollers 33 and i3 3 and the arcuate sectors HM and i62 on the limit arms l5? and 558, otherwise the thumb screws and/or M8 on said armature [94 are adjusted so that there is suflicient clearance between said rollers M3 and i3 5 and said sectors ifil and H52.

Upon energization of the magnetic coil Hi2, the attraction of armature its frees said contact arms i2! and i273 so that the rollers i553 and H34 thereon move into the paths of the sectors l5! and il -.12 on limit arms till and but such energization of the magnetic coils ltilb and I620 is selectively controlled and takes place only when the elevator car it i near the corresponding floor we, lflb or 20 in a r anner next to be described.

The energizing circuit for each magnetic coil includes a pair of zone contacts its and I64 ch normally open, contact E54 being operated by an actuating rod Said actuating rod i is ositioned so as to be operated by the zone a whereupon contacts i233 and E54- iosed, see Figs. 3 and l. The zone arm H53 lgned and angularly adjusted on shaft l5! so tnat said contacts and i6 3 are closed only the elevator car it is in the vicinity of the r corresponding to the particular set of contacts i623 and and zone arm i515. Contact I63 is connected to one side of magnetic coil I02 by a wire I66.

The several control circuits are connected to supply main LI by a bus wire I61, see Fig. 1. The energizing circuit for leveling relay 990 comprises a wire I680 extending from bus wire I61 to zone contact I630, a wire I660 extending from zone contact I640 to one side of magnetic coil I020, and a wire I690 extending from the other side of magnetic coil I020 to bus Wire 14. The energizing circuit for leveling relay 990 includes a wire I68b extending from bus wire I61 to zone contact I631), a wire I661) extending from zone contact I64b to magnetic coil I02b, and a wire I69b extending from magnetic coil I021) to bus wire 14. The energizing circuit for leveling relay 990 includes a wire I680 extending from bus wire I61 to zone contact I630, a wire I660 from zone contact I640 to magnetic coil I020, and a wire I690 from magnetic coil I020 to bus wire 14.

The motor control contacts I08 and I09 on the armature I04 are each connected to bus wire I61, motor control contact I090 being connected to bus wire I61 by wire I100, and motor control contact I080 being connected to bus wire I61 by a wire I1I0. Wires I10b, I1Ib, I100 and I1Ic, respectively, connect motor control contacts I091), I081), I090 and I080 to said bus wire I61. The motor control contacts I280, I28b and I280 on the contact arms I230, I23b and I230 are respectively connected by wires I120, I12?) and I120 to a wire I13 which leads to one side of the coil 86 of up leveling contactor 85, the other side of said coil 86 being connected to bus wire 14 by a wire I14. The motor control contacts I250, I251) and I250 on contact arms I2I0, I2Ib and I2I0 are respectively connected by wires I150, I15!) and I150 to a wire I16 which extends to one side of coil 93 of the down leveling contactor 92, the other side of said coil 93 being connected to bus wire 14 by a wire I11.

There are two motor control circuits for each floor, one circuit being an up leveling control circuit and the other a down leveling control circuit. For instance the up leveling control circuit for floor I20 may be traced as follows: from supply main LI, wire I61, wire I100, contacts I090 and I280 respectively on armature I040 and contact arm I230 of leveling relay 990, wire I120, wire I13, up leveling contactor coil 86, wire I14, bus wire 14, through contacts 15 and contact arm 83 to supply main L2. The down leveling control circuit for floor I20 is from supply main LI, wire I61, wire I1I0, contacts I080 and I250 respectively on armature I040 and contact arm I230 of leveling relay 990, wire I150, wire I16, down leveling contactor coil 93, wire I11, bus wire 14, through contacts 15 and contact arm 83 to supply main L2. The up and down leveling motor control circuits for the other floors are similar to those just traced and it is pointed out that the motor control contacts are paired so that motor control contacts I090 and I280, I080 and I250, I090 and I280, I08b and I251), I090 and I280, I080 and I250, make or break contact with each other to close or open the respective motor control circuits.

The operation of the automatic elevator leveling system according to the present invention will now be described.

When the elevator car I4 is stopped at a floor, the contactors 62, 68, 16, 85 and 92 are all in their normally open positions and all motor control circuits and all motor circuits are open. Fig. 1 illustrates another condition with up leveling contactor 85 in closed position which should not be confused with the conditions when the elevator is stopped at any particular floor.

Assume that the operator on the car I4 moves the car switch 48 upwardly. The up terminals 49 and 50 of said car switch 48 are bridged and up contactor 62 is placed across supply mains LI and L2. Upon energization of up contactor 62, rod 64 is raised, contact arm 66 closes contacts 26, contact arm 61 closes contacts SH, and contact arm 65 closes contacts 59 so that coil 11 of high speed contactor 16 is energized. Such energization of said coil 11 moves rod 10 against the action of spring 84 so that contact arm 89 closes contacts 29 and contact arm 8i closes contacts 21. The three phase high speed winding 23 of the motor I8 is now fully energized and the car I4 will be raised at full speed.

At the same time energization of coil 11 has moved rod 82 to withdraw contact arm 83 from contacts 15 and since all other energizing or control circuits are fed through contacts 15 they can not now become operative during high, spear operation of the car I4. For instance each time that car I4 approaches one of the floors I20, I20 or IE0, the zone arms I530, I531) or E330 close the contacts I630 and I640, I63!) and I641), I630 and I640, respectively, but since contacts 15 are open, none of the energizing circuits or magnetic coils I02 can be energized so that the leveling relays 99a, 99b and 990 maintain the position illustrated in Fig. 2 and the sectors I6I and I62 of limit arms I51 and I50 pass rollers I33 and I34 without engaging the same.

When the car is approaching a floor I2 at which it is desired to stop, the operator moves the car switch 48 to the open position shown in Fig. 1. Assuming that the car has been moving upwardly toward floor I20, see Fig. 1, the contactors 62 and 16 are opened and the high speed winding 23 of motor I8 is cle-energized. At the same time, however, zone arm I530 has operated actuating rod I650 to close zone contacts I630 and I640. Now since contactor 16 is de-energized contacts 15 are closed by contact arm 83 and magnetic coil I020 is energized through the energizing circuit, as previously traced, between supply mains LI and L2. Furthermore, the arcuate sector I620 on limit arm I580 is now in position to engage the roller I340 on contact arm I230, see Fig. 1, and hold the motor control contact I280 therein in position to make with the contact I090 on armature I040 which is now attracted by magnetic coil I020. On the other hand, the arcuate sector I6I0 on limit arm I510 is not opposite roller I330 so that contact arm I 2I0 swings to inoperative position against the thumb screw I36 and motor control contacts I02-0 and I250 remain open.

Since motor control contacts I090 and I280 are closed, the motor control circuit to up leveling contactor 85 is completed across supply mains Li and L2 so that the coil 86 is energized and the rod 88 is operated to move contact arm 09 against contacts 39, contact arm 90 against contacts 4|, and contact arm 9| against contacts 31. Closure of said contacts 31, 39 and 4| places the three phases of the low speed motor Winding 24 across the three phase supply mains Ll, L2 and L3 so that the elevator I4 continues to move up wardly but at low speed. Since contacts I380 and I250 are open, down leveling contactor 9? can not be energized. This condition of the zone arm I530, zone contacts I630 and I640 being closed, blocking of contact arm I230 by limit arm [58a to close motor control contacts lfl9a and Mia upon energization of magnetic coil Wild and energization of up leveling contacting 85 to close the motor circuits to the low speed up winding 24 of the motor I3 is indicated in Fig. 1.

The elevator car is now moving upwardly at low speed. The arcuate sector ltfia and limit arm l58a are so designed and located so that roller Nita is disengaged and contact arm l23a moves to its normal position under the action of spring Ml which also causes a quick break between motor control contacts iUSid and izlia precisely when the platform of the elevator car l4 becomes even or level with the floor 52a. Opening of contacts lii8a and @2067 de-energizes upleveling contactor 35 to open contacts 3?, 39 and M and de-energizes the motor winding 24 so that the car M is stopped. In case the opening of contacts lElQa and l28a is not timed just right, the limit arm 558a may be angularly adjusted on shaft 55 to correct the time for opening of said contacts lBSa and IZBa or the adjustable mountings for contacts 589a or 128a may be adjusted by appropriate adjustment of nuts I [4 or 83% to retract or project said contacts.

If the car switch 33 is moved downwardly to bridge the down terminals 51 and 52 thereof, down contactor S8 and high speed contactor '86 are energized and the high speed winding 23 of motor I8 is connected across supply mains Ll, L2 and L3 in such phase relation that the motor I8 is reversed and the car It moves downwardly. At the same time contacts 75 are opened so that none of the leveling control circuits can be energized.

Opening of the car switch 48 as the car 84 is lowered toward a floor at which it is desired to stop will de-energize the high speed motor winding 23 and contacts it: will be closed by the concurrent de-energization of high speed contactor l6. Assume that the car it is moving downwardly toward floor i2b, zone arm I531) will be in engagement with actuating rod i651? and zone contacts H531) and i642) will be closed to complete the energization circuit through magnetic coil 32b. Limit arm ll'o'i'b is so located or timed that its arcuate sector Hill) is now in position to engage roller I332) when armature NW) is energized and contact arm i2ib is swung upwardly so that contacts i631) and i251) are closed. However, since the car M is moving downwardly roller 13 is not engaged by the sector i622: on limit arm i581) so that contacts H3919 and I282) are open under these conditions which are illus trated in Fig. 4.

Since contacts H381) and i251) are closed, the motor control circuit to down leveling contactor 92 will be completed across supply mains Li and L2 and the low speed down motor contacts d3, 35 and 47 will be closed by contact arms 98, 9V and 98, respectively, of said down leveling contactor Q2. The car it is now moving downwardly at low speed and said arcuate sector Hill) on limit arm it'll) disengages roller i331) under the action of spring 114% to open motor control contacts iilfib and i251) precisely so that down leveling contactor 92 is lie-energized and said low speed down motor contacts 43, 55 and 41 are opened to stop said car It with its platform level with floor l2b. Again in case this timing is not quite accurate limit arm i571) may be angularly adjusted on shaft E55 or contacts l08b and I25a may be adjusted to correct the timing.

If, for any reason, such as slip in the brake or cable stretch, the car t4 should overshoot the floor at which it is stopping the other roller will ride up on the arcuate sector of the other limit arm and the motor control contacts for moving the car in the opposite direction will be closed. Specifically, if such over shooting took place during the down leveling at floor l2b as just described, rcller 534?) would ride up on arcuate sector 5152b so that contact arm 5232) would be moved to close motor control contacts HlSb and l28b. It should be noted that the limit arms l5! and E58 are moved independently of the main cable NS for the car l4 so that stretching thereof does not affect th proper timing or positioning of said limit arms. Since the up motor control contacts i 8% and i281) are closed by such downward overshooting, up leveling contactor 85 is energized and the car moves upwardly at low speed but now under the control of limit arm M21). The cessation of this return movement is then controlled as previously explained with respect to the up leveling conditions.

It should also be noted that zone contacts H63 and I64 are always closed by zone arm 853 when the car is at or near the corresponding floor I2 and irrespective of whether the car I4 is moving or is stopped. Hence if for any reason the car M should raise or drop after having come to a stop level with the floor, the corresponding levelin relay 99 remains energized and the proper roller E33 or 136 rides up on the corresponding sector Hit or H62 so that the leveling operations are repeated to re-level the car with respect to the floor. The extreme normal positions of rollers i153 and we are predetermined by the adjustment of thumb screws i365 so that said rollers E33 and 53 1 will ride up on said sectors Hi! and E62 during the re-leveling functions of the leveling relay 99.

The zone arms W3 and limit arms l5] and H8 are preferably timed with respect to each other so that the magnetic coil i532 of the leveling relay is not energized at least until the leading edge of the arcuate sectors lBl and 562 are in position to engage either roller i33 or ltd respectively. This condition is assured because the zone arms i533 move through a relatively small angle since they are operated through reduction gears H29 and use while limit arms l5? and 958 are moving at greater than car speed and travel through a relatively large angle.

One outstanding feature of the automatic elevator leveling system of the present invention is that the leveling relays 99, zone arms I53 and limit arms l5? and i583 may all be located at one place such as in the pent-house or motor room above the elevator hatchway. Hence it is a simple matter to make any of the necessary adjustments to control the operation and accurate leveling of the car. Such adjustments, as have been previously explained, may be angular adjustment of the zone arms E53 upon shaft l5! by means of set screws EM, may be angular adjustment of limit arms i511 and [58 upon shaft H55 by means of set screws its and 160, respectively,

to alter the timing of said limit arms l5! and- 558 with respect to said zone arms i5? and of the arcuate sectors it! and M2 on limit arms i5! and @558 with respect to said rollers E33 and 93 respectively, or may be leveling relay adjustments such as adjustment of the motor control contacts W8 and M9 by means of nuts iii and M4 and motor control contacts I25 and H8 by means of nuts iZ'l and itt for fine adjustment of the timing of the motor control contacts, such as adjustment of the thumb screws H7, H8, I36

and I38 to vary the extreme positions of the contact arms iii and I23 for clearance between sectors IEI and I62 and rollers I33 and H4, see Fig. 2, and for adjustent of the normal inoperative positions of said contact arms HI and I23, see Fig. 3.

Although the high speed motor control circuits are completed and opened by the car switch 48, it is obvious that other types of motor control switches, such as push buttons, may be used at the floors or on the cars. It is also understood that standard equipment such as brakes, gate switches, interlocks, etc., will in general be used with the leveling system of the invention but such equipment has not been illustrate-d or described because the provision and application thereof will be realized by those skilled in the art.

Since many variations of the invention are possible, the present disclosure and description are to be construed in an illustrative sense, the scope or said invention being defined in the appended claims.

Having now particularly described my invention, what I desire to secure by Letters Patent of the United States and what I claim is:

1. In an automatic system for leveling an elevator car with respect to a floor, the combination with a prime mover connected to said elevator car and for moving the same with respect to said floor, controlling means associated with said prime mover for controlling the operation thereof, a control circuit including a control coil for operating said controlling means and including a pair of control contacts, and a leveling relay including an armature carrying one of said control contacts, including a contact arm carrying the other control contact, and including a magnetic coil adapted upon being energized to attract and hold said armature in position for engagement of the control contact thereon with the control contact on said contact arm, of an energizing circuit including zone contacts and said magnetic coil, a zone arm connected to said car and adapted to close said zone contacts for energization of said magnetic coil only when said car is near said floor, and a limit arm connected to and having a movement corresponding to the movement of said car, for engaging said contact arm to hold it and the control contact thereon in position for contact with the control contact on said armature upon energization of said magnetic coil, and disengaging said contact arm to open said contacts and said control circuit so that said controlling means is operated to stop said prime mover precisely when the car is level with said floor.

2. In an automatic system for leveling an elevator car with respect to a floor, the combination with a motor connected to said elevator car and for moving the same with respect to said floor, a motor circuit including motor contacts and said motor, a motor control circuit including a contactor for operating said motor contacts and including a pair of motor control contacts, and a leveling relay including an armature carrying one of said motor control contacts, a contact arm carrying the other motor control contact, and including a magnetic coil adapted upon being energized to attract and hold said armature in position for engagement of the control contact thereon with the control contact on said contact arm, of an energizing circuit including zone contacts and said magnetic coil, a zone arm connected to said car and adapted to close said zone contacts for energization of said coil only when said car is near said floor, and a limit arm connected to and having a movement corresponding to the movement of said car, for engaging said contact arm to hold the motor control contact thereon in position for contact with the other motor control contact upon energization of said coil, and adapted to disengage said contact arm and permit separation of said control contacts.

3. In an automatic system for leveling an elevator car with respect to a floor, the combination with a motor connected to said elevator car and for moving the same with respect to said floor, a motor circuit including motor contacts and said motor, a motor control circuit including a contactor for operating said motor contacts and including a pair of motor control contacts and a leveling relay including an armature carrying one of said motor control contacts and normally in an inoperative position, a magnetic coil adapted upon being energized to move said armature to an operative position, and a contact arm carrying the other motor control contact and normally in an inoperative position irrespective of the energization of said magnetic coil, of an energizing circuit including zone contacts and said magnetic coil, a zone arm connected to said car and for closing said zone contacts to energize said magnetic coil and attract said armature only when said car is near said floor, and a limit arm connected to said car to move at a speed corresponding to car speed and for maintaining said contact arm in operative position as said car approaches said floor whereby said motor contacts are closed.

4. In an automatic system for leveling an elevator car with respect to a floor, the combination with a motor connected to said elevator car and for moving the same with respect to said floor, a motor circuit including motor contacts and said motor, a motor control circuit including a contactor for operating said motor contacts and including a pair of motor control contacts, and a leveling relay including an armature carrying one oisaid motor control contacts, having an abutment and normally in an inoperative position, a magnetic coil adapted upon being energized to move said armature to operative position, and a contact arm carrying the other motor control contact and normally in an inoperative position irrespective of the energization of said magnetic coil, of an energizing circuit including zone contacts and said magnetic coil, a zone arm connected to said car and for closing said zone contacts to energize said magnetic coil and attract said armature to operative position only when said car is near said floor, and a limit arm connected to said car to move at a speed corresponding to car speed and for maintaining said contact arm in operative position as said car approaches said floor, said abutment on the armature engaging said contact arm normally to maintain the same out of the path of said limit arm when said magnetic coil is not energized.

5. In an automatic system for leveling elevators, the combination with an elevator assembly including a hatchway having a plurality of floors, an elevator car movable within said hatchway, and a prime mover connected to said elevator car and for moving the same with respect to said floor, controlling means associated with said prime mover for controlling the operation thereof, a control circuit including a control coil for operating said controlling means and including a plurality of pairs of control contacts, each corre- I sponding to one of said floors, and a plurality of. leveling relays each corresponding to one of said floors and to one pair of control contacts and each including an armature carrying one of the respective pair of control contacts, a contact arm carrying the other control contact of said pair, and each including a magnetic coil adapted upon being energized to attract and hold said armature in position for engagement of the control contact thereon with the control contact on said contact arm, of a plurality of energizing circuits each including a pair of zone contacts and the magnetic coil of one of said leveling relays, a plurality of zone arms connected to said car and each adapted to close the corresponding zone contacts for energization of the respective magnetic coil only when said car is near the corresponding floor, and a plurality of limit arms all connected to said car to move at a speed corresponding to car speed, each for engaging the corresponding contact arm of the respective leveling relay to hold it and the contact thereon in position for contact with the control contact on the associated armature upon energization of the corresponding magnetic coil, and each dis engaging the corresponding contact arm precisely when the car is level with the respective floor to permit disengagement of the control contacts on the energized leveling relay.

6. In an electro-mechanical automatic system for leveling an elevator car with respect to a floor, the combination with a motor connected to said elevator car and for moving the same with respect to said fioor, and a leveling relay for each floor and including a pair of normally open motor control contacts, a contact arm carrying one of said motor control contacts, an armature carry-- ing the other of said motor control contacts, and a magnetic coil for attracting said armature to close said motor contact, of an energizing circuit connected to said magnetic coil and including a pair of zone contacts, and a mechanical control means connected to said elevator car, including azone arm for closing said zone contacts only when said car is adjacent to said floor to energize said coil and close said motor control contacts, and including a limit arm moving at a speed corresponding to car speed for engaging said contact arm to maintain said motor contacts closed as the car approaches said floor and for permitting said motor contacts to open just as the car becomes level with said floor.

'7. In an automatic leveling system for elevators, the combination with an elevator car within a hatchway having a plurality of landings, a motor connected to said elevator car and for moving the same within said hatchway, a leveling relay for each landing and including two pairs of control contacts, two contact arms each carrying one contact of each pair of control contacts, a magnetic coil, and an armature carrying the other contact of each pair of control contacts, a mechanical control means connected to said elevator car, including a set of zone arms rotating only once for each passage of said car through said hatchway, and including a set of pairs of limit arms rotating at a speed corresponding to car speed, an energizing circuit connected to the magnetic coil of each leveling relay and including a pair of zone contacts which are closed by the corresponding zone arm as the car approaches a landing, and a motor control circuit including said control contacts which are opened by the appropriate limit arm when a car is level with the landing.

8. In a leveling system for elevators, the combination with an elevator car within a hatchway with a plurality of landings, a reversible motor connected to said elevator car and for moving the same within said hatchway, and a leveling relay for each landing and including two pairs of normally opened motor control contacts, a pair of contact arms each carrying one of each pair of said motor control contacts, a single armature carrying both of the other of said pair of motor control contacts, and a magnetic coil for attracting said armature to close said motor control contacts, of a plurality of holding circuits each connected to the magnetic coil of each leveling relay and including a pair of zone contacts, an up motor control circuit including one pair of motor control contacts on said leveling relay, a down motor control circuit including the other pair of motor control contacts on said leveling relay, and a mechanical control means connected to said elevator car, including a zone arm for closing said zone contacts only when said car is adjacent to the corresponding landing to energize said magnetic coil and attract said armature, and including a pair of limit arms moving at a speed corresponding to car speed and each for engaging one of said contact arms alternatively, one of said limit arms engaging the contact arm carrying one of the motor control contacts in the up motor control circuit to maintain said contacts closed while the car is moving upwardly toward said landing, and the other of said limit arms engaging the other contact arm carrying one of the motor control contacts in the down motor control circuit to maintain said contact closed while the car is moving downwardly to said landing, neither of said limit arms engaging the respective contact arms when the car is level with the landing in which position both pairs of contacts are normally open.

9. In a leveling assembly for an elevator car, the combination with a limit arm having the end thereof moving with the elevator car and through a distance corresponding to the travel of said car, of a leveling relay comprising a contact arm movably mounted and located normally to assume a position in the path of and adapted to bear against said limit arm, an armature movably mounted norm-ally to assume an inoperative position, an abutment adjustably connected to said armature and adapted during inoperative position of said armature to engage said contact arm and hold it out of the path of said limit arm, and a magnetic coil positioned and adapted upon being energized to move said armature into operative position and for disengagement of said abutment and said contact arm so that said contact arm may move into the path of said limit arm.

10. In a leveling assembly for an elevator car, the combination with a limit arm having the end thereof moving with the elevator car and through a distance corresponding to the travel of said car, of a leveling relay comprising a base member, a contact arm movably mounted thereon and located normally to assume a position in the path of and adapted to bear against said limit arm, a stop on said base member and for limiting the normal movement of said contact arm into the path of said limit arm, an armature movably mounted on said base member normally to assume an inoperative position and engaging said contact arm to hold it out of the path of said limit arm, and a magnetic coil positioned and adapted upon being energizedto move said armature into operative position, in which position said contact arm is free normally to move into the path of said limit arm and into engagement with said stop which determines the ultimate position of said contact arm.

11. Ina leveling assembly for an elevator car, the combination with a limit arm having the end thereof moving with the elevator car and through a distance corresponding to the travel of said car, of a leveling relay comprising a base member, a contact arm movably mounted thereon and located normally to assume a position in the path of and adapted to bear against said limit arm, an armature movably mounted on said base member normally to assume an inoperative position and having an abutment engaging said contact arm to hold it out of the path of said limit arm, and a stop on said base member for engaging said contact arm to limit the movement of said contact arm out of the path of said limit arm by the abutment on said armature.

12. In a leveling assembly for an elevator car, the combination with a limit arm having the end thereof moving with the elevator car and through a distance corresponding to the movement of said elevator car, of a leveling relay comprising a contact arm movably mounted and located normally to assume a position with a portion of said contact arm in the path of and adapted to bear against the end of said limit arm, a contact on said contact arm, an armature movably mounted to assume an inoperative position, a second contact adjustably mounted on said armature and for engaging said contact on the aforementioned contact arm, and a magnetic coil positioned and adapted upon being energized to move said armature and adjustable contact toward said contact arm for closure of said contacts at a time determined by the adjustment of said adjustable contact.

13. In an automatic system for leveling an elevator car with respect to a floor, the combination with a pair of limit arms having the ends thereof moving with the elevator car and through a distance corresponding to the movement of said elevator car, of a leveling relay comprising a pair of contact arms movably mounted and each located normally to assume a position with a portion thereof in the path of and to bear against the end of the respective limit arm, a contact on each of said contact arms, an armature movably mounted normally to assume an inoperative position and having a pair of parts for engaging respective contact arms and adapted to hold each contact arm out of engagement with the respective limit arm, a pair of contacts on said armature, and a magnetic coil positioned and adapted upon being energized to move said armature toward said contact arm, said limit arms being relatively displaced, one of said limit arms engaging one contact arm when the elevator car is above said floor for closure of the corresponding contact on the armature and said one contact arm, and the other of said limit arms engaging the other of said contact arms when the elevator car is below said floor for closure of the corresponding contact on the armature and said other contact arm.

14. In an automatic system for leveling an elevator car with respect to a floor, the combination with a pair of limit arms having their ends angularly displaced and rotating through a distance corresponding to the travel of said car, of a leveling relay comprising a pair of contact arms movably mounted and located normally to as-- sume a position with each contact arm in the path of and adapted to bear against one of said limit arms, a contact on each contact arm, an armature movably mounted, adapted normally to assume an inoperative position and for holding said contact arm out of the path of the respective limit arm, a pair of contacts on said armature, and a magnetic coil positioned and adapted upon being energized to move said armature toward said cont-act arm and releasing said contact arm to permit normal movement thereof, one of said limit arms engaging one of said contact arms when said elevator car is above said floor to hold said one contact arm in position for closure of the corresponding contact on the armature and the engaged contact arm upon energization of said coil, the other of said limit arms alternatively engaging the other of said contact arms when said elevator car is below said floor to hold the other said contact arm in position for closure of the corresponding contact on the armature and the engaged contact arm during energization of said coil, and neither of said limit arms being opposite said contact arms when the elevator car is level with said floor to permit both of said cont-act arms to move to normal inoperative positions to open simultaneously in spite of the energization of said coil.

15. In a leveling assembly for an elevator car,

the combination with a limit arm having the end thereof moving with the elevator car and through a distance corresponding to the movement of said elevator car, of a leveling relay comprising a contact arm movably mounted and located normally to assume a position with a portion of said contact arm in the path and adapted to bear against the end of said limit arm, a contact on said contact arm, an armature movably mounted normally to assume an inoperative position and having a part for engaging said contact arm to hold the same out of engagement with said limit arm, a second contact on said armature, and a magnetic coil positioned and adapted upon being energized to move said armature toward said contact arm for closure of the contacts thereon as long as said contact arm bears against said limit arm, said contacts being separated upon disengagement of said contact arm and said limit arm even though said magnetic coil is energized.

16. In a leveling assembly for an elevator car, the combination with a limit arm having the end thereof moving with the elevator car and through a distance corresponding to the travel of said car, of a leveling relay comprising a contact arm movably mounted and located normally to assume a position in the path of and adapted to bear against the end of said limit arm, a contact on said contact arm, an armature movably mounted normally to assume an inoperative position and for engaging said contact arm to hold the same out of the path of said limit arm, a second contact on said armature, a magnetic coil positioned and adapted upon being energized to move said armature toward said contact arm for closure of the contacts thereon during engagement of said contact arm and said limit arm, and a resilient means between said armature and said contact arm, tending to separate said arms and causing separation of said contacts immediately upon disengagement of said contact arm and said limit arm.

17. In a leveling system for an elevator car moving with respect to a landing, the combination with a shaft connected to said elevator car,

a limit arm on said shaft and having its end moving through a distance corresponding to the travel of said elevator car, and an adjustable connection between said shaft and said limit arm, of a leveling relay comprising a contact arm movably mounted and located normally to assume a position with said contact arm in the path of and adapted to bear against said limit arm, a contact on said contact arm, an armature movably mounted and adapted normally to assume an inoperative position and having a part for engaging said contact arm to hold the same out of engagement with said limit arm, a second contact upon said armature, and a magnetic coil positioned and adapted upon being energized to move said armature toward said contact arm for closure of the contacts thereon during engagement of said contact arm and said limit arm, said contacts being separated, even though said coil is energized, upon disengagement of said contact arm and said limit arm, the moment of said disengagement being variable to take place precisely when the car is level with said landing by adjustment of the limit arm with respect to said shaft.

18. In an electro-mechanical relay, the combination with a base, an electro-magnetic coil mounted upon said base, an armature pivoted on said base normally to swing away from said coil but adapted to be attracted toward said coil upon energization thereof, a contact arm carrying a contact on one end and a roller on the other end thereof and intermediately pivoted to said base, a pair of stops adjustably mounted upon said base, one to limit the rotation of said contact arm in one direction and the other to limit the rotation of said contact arm in the opposite direction,-a second contact adjustably mounted upon said armature and positioned so as to engage the contact on said contact arm when said coil is energized, an abutment adjustably mounted on said armature and for engaging said contact arm to hold the same against one of said stops during normal position of said armature, a spring arm between said armature and said contact arm and for normally separating the contacts thereon but adapted to be overcome for engagement of said contacts upon energization of said electromagnetic coil, and a limit arm for engaging the roller on said contact arm to hold the contact on said contact arm in position for engagement with the other contact upon energization of said coil.

19. In an electro-mechanical relay, the combination with a support, a contact arm carrying a contact and movable to a contacting position, a magnetic arm also carrying a contact, normally in an inoperative position and movable to an energized position, a resilient means between said magnetic arm and said contact arm for separating the same and the contacts thereon, a control member for engaging said contact arm and moving the same to contacting position, and a coil adjacent said magnetic arm and adapted upon being energized to move said magnetic arm to energized position and to move the contact thereon into contact with the contact on said contact arm, said resilient means being adapted upon disengagement of said control member and said contact arm to separate the contacts on said magnetic and control arms even though said coil is still energized.

JAMES H. BARTHOLOMEW. 

